[Bug target/116979] [12/13/14/15 regression] fma not always used in complex product

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116979

--- Comment #19 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Uroš Bizjak from comment #18)
> (In reply to Jakub Jelinek from comment #17)
> > Not marking as fixed for GCC 15 yet, as there is the scalar cost computation
> > issue unresolved.
> There is also a issue how the final result for SFmode is constructed. It can
> be seen when compiled with -ffast-math:
> 
>         vmovshdup       %xmm0, %xmm4
>         vmovss  %xmm0, -8(%rsp)
>         vmovss  %xmm4, -4(%rsp)
>         vmovq   -8(%rsp), %xmm0
> 
> This will result in store forwarding stall.

That looks like a backend issue?  A missed vec_init patttern?